JP2008-25694A discloses a uniflow cylinder device in which a relief valve causing resistance to flow of working oil passing therethrough is provided on a bottom member that closes an end of an outer tube.
With the above-mentioned cylinder device, a reservoir tank is formed between an inner tube and the outer tube. In the reservoir tank, a pipe is disposed for guiding the working oil that has been discharged from a rod-side chamber to the bottom member. With this configuration, the working oil that has been discharged from the rod-side chamber is allowed to return to the reservoir tank through the relief valve provided on the bottom member.